Rebaudioside A Purification Section
The next and final step of steviol glycoside purification process is the seperation and purification of Reb A.
The solid glycoside mix (TSG) is dissolved in a specific hot water alcohol mixture under refluxing condition and then cooled to crystallize Reb A crystalls. The dissolution and crustallization is done in the same jacketted vessel provided with a motorized stirrer. During the dissolution process the mixture is heated by passing steam through the jacket of the vessel. Then, for crystallization, the solution is cooled by passing cold water through the jacket.
The crystallized Reb A can be seperated from the mother liquor by basket centrifuge and dried in vacuum tray dryers.
The mother liquor is then sent for concentration by nano filtration followed by vacuum evaporation, decolorization by active carbon treatment. Lower grades of TSG is prepared by spray drying of this concentrated mother liquor.